Apparatus employed in wireless telegraphy.



a. m Ancom. APPARATUS EMPLOYED IN WIRELESS TELEGBAPHY.

(Application filed Oct. 12, 1899.)

No. 650,l09. v Patented May 22, I900.

( No Modal.)

v M m 4 3" U TED STATES PATENT OFFICE.

eUeLIELMo MARCONI, OF LONDON, ENGLAND, ASsIeN'oR TO THE WIRELESS TELEGRAPH AND SIGNAL COMPANY, LIMITED, on SAME PLAcE.

APPARATUS EMPLOYED I'N'WIRELESS TELEGRAPHY.

SPECIFICATION forming part of Letters Patent N 0. 650,109, dated May 22, 1900. Application filed October 12, 1899. Serial No. 733,413. N m de To all whom it may concern:

Be it known that I, GUGLIELMO MARCONI, electrician, a subject of the King of Italy, residing at 28 Mark Lane, in the city of London, England, have invented certain new and useful Apparatus Employed in Wireless Telegraphy, of which the following is a specification.

In the specification of a former patent, dated the 13th day of July, 1897, No. 586,193, an arrangement is described in which the transmitter consisted of a sparking appliance hav-' ing one terminal connected to an insulated conductor'in the air and the other terminal to earth, while'the receiver contained a sensitive tube or sensitive imperfect contact hav- 7 ing one end connected toa similar conductor the operator or to injure the imperfect contact.

The object of this invention is to remove this inconvenience and also to render it impossible for the operator to accidentally operate his transmitter, and thereby cause a spark when the aerial conductor at his station is connected to the receiver, which might injure the imperfect contact.

According to this invention the aerial conductor is'permanently connected to one terminal of the sparking appliance, and therefore if a Ruhmkorif coil or transformer is used the aerial conduct-or will be connected 'toearth through its secondary winding, thus preventing the accumulation of atmospheric electricity in it, while it is found that the electrical oscillations falling upon it from the transmitter of the correspondent station cannot readily traverse the convolutions of the coil, but prefer to pass to earth through the receiver when the said aerial. wire is connected to it. The signals are sent, as before, by means of a Morse key in a local-battery States patent, No. 624,516. 7

can also be applied to receivers described in circuit through the primary of the Ruhmkorff coil or transformer.

According to this invention the arm of the key is prolonged beyond its pivot and-carries an insulated terminal which is permanently connected to'the terminal of the sparking appliance, and therefore to the aerial conductor. Below this terminal there is on the base of the instrument the terminal of the receiver.

The arm is so arranged that immediately it is released by the operator after sending a message it turns about on its pivot, bringing the above-mentioned conductors together, thus connecting the receiver to the aerial conductor.

The drawing is a diagram ofa combined transmitting and receiving station arranged in accordance with this invention.

The letters, so far as they are applicable, are the same as'those employed in the former specification. i

a is a battery, and b an ordinary Morse key closing the circuit through the primary 'of a Ruhmkorif coil 0, the terminals-of the seoa ondary being connected to metallic balls e. The aerial conductor a is permanently con nected to one of the balls 6, the other being connected to earth E. The keyb has two contacts b 19 insulated from each other. The diagram shows the key inithe position for sending, the contact I) touching the contact 12 and closing the circuit of the battery ct through the primary of the induction-coil c.

Immediatelythe key is released by the operator its longer arm falls by its own weight, the contact-h descending onto the contact 5 which is connected to th'ereceiver R by the wire M.

It is found advantageous to insert an impedance-coil d between the terminal of the in duction-coil used for sending and the sphere, which is connected to the aerial conductor.

The receiver R is inclosed in a-box R, of conducting material, and may be such and so connected as is described in my former United The invention the specification of the patent dated the 13th day of July, 1897, No. 586,193. The means adopted for protecting the receiver are preferably those described in the specification-t the patent dated the 27th day of J nne, 1899, No. 627,650. The wire connecting the receiver to the terminal on the base of the key 7 receiver should preferably be connected to- 1 should preferably be inclosed in a metal tube N to protect it from the oscillations of the local transmitter, and the tube N shoiild be electrically connected to the box B. This invention is also applicable if the earth connection is snbstitntedby a capacity area. In

this case the capacities of the transmitter and gether. i

I I claim-' 1. The combination of the primary and sec ondary of a sparking appliance, a battery and key in circuit with the primary, an aerial conductor connected to one terminal of the secondary, a receiver, means for connecting the cotin'e'ction 'connected to the other terminal.

S3; The combination of the'primary and secondary'ofa sparking appliance, a battery in eircnit'with the primary, an aerial conductor connected to one terminal of the secondary, receiver, two fixed contacts one connected'to one terminal of the primary and the other to the receiveiy a pivoted arm and two contacts on'the arm insdl'atd from each other an'd op posite the fixed contacts one being connected to theother terminal of the primary and the other to that terminal of the' secondary which is connected to the aerial conductor,

4.. The combination of the primary and secondary of a'sparkin gap 1 i ance,-a battery in 'circiiit with the primary, an aerial conductor connected to one terminal of the secondary, an earth connection connected to theother terminal, a receiver, two fixed contacts one connectedto one terminal of the primary and the other to the receiver, a pivoted a'n'n'and two contacts on the arm insulated fromjeach other and opposite the fixed contacts one be ing connected to the other terminal of the primary and the other to that termin-alvo'f the secondarywhich is connected to the aerial conductor. v g GUGLIELMO MARcdiiL Witnesses: a

HAROLD G. VILLARD, EDWARD C. DAVIDSON.

a capacity connected to the other terminal, a 

